Biotransformation of furanic compounds is receiving increasing attention. This is both in respect of the bioproduction of furan-2,5-dicarboxylic acid (FDCA), which is a promising value added chemical from biomass (Werpy et al. (2004)), and in respect of their negative role in the fermentative production of biofuels and biochemicals from lignocellulose containing materials (Almeida et al. (2009)).
Recently a furanic compound utilising organism, Cupriavidus basilensis HMF14, has been isolated (Koopman et al. (2010a). This organism is capable of metabolizing furfural and 5-(hydroxymethyl)furan-2-carbaldehyde (HMF). The furfural and HMF degradation pathway of Cupriavidus basilensis HMF14 has been disclosed by Koopman et al. (2010a) together with the genes involved.
The functional introduction of the hmfH gene from Cupriavidus basilensis HMF14 in Pseudomonas putida S12 is disclosed by Koopman et al. (2010b). The resulting strain has good FDCA production capabilities using HMF as a substrate. However, the observed accumulation of 5-(hydroxymethyl)furan-2-carboxylic acid (HMF-acid) would require long process times or alternative measures to remove this by-product. Sufficient removal of the HMF-acid by-product is desirable for many of the applications for which the FDCA may be produced and sometimes even is essential.
In search of a solution of the problem of HMF-acid accumulation, the inventors of the present invention have now surprisingly found that expression of certain polypeptides in the Pseudomonas putida S12 FDCA production system, effectively reduces HMF-acid accumulation.